The first aim of this research will be to develop optimum parameters for an assay which quantitatively measures the degree of lymphocyte transformation that occurs in response to an antigenic stimulus by monitoring early changes in the polyamine metabolism (ornithine decarboxylase activity and putrescine uptake) of activated lymphocytes. This new, quantitative method of assessing lymphocyte responsiveness will be used to investigate the role of immunologic involvement in mammalian pregnancy. It has been postulated that immunologic enhancement (a state of specifically impaired cellular immunologic activity resulting from the presence of alloantibody) functions to protect the fetus from immunologic destruction. To test this hypothesis, C57 mice, pregnant by CBA males will be tested for ability to respond to CBA antigens in one-way mixed lymphocyte culture (MLC). Similar experiments will also be carried out using the marmoset, a small South American primate. Tissues that rapidly synthesize protein or undergo mitosis show a rapid, dramatic increase in ornithine decarboxylase (ODC). Because ODC activity and subsequent polyamine formation is closely associated with RNA metabolism prior to DNA synthesis, the monitoring of ODC may detect cellular activity of tissues about to undergo rapid proliferation. Such proliferation occurs when activated lymphocytes respond to antigenic stimuli in mixed lymphocyte cultures. Preliminary data indicates that allogenic MLC exhibit an ODC activity 5-10 fold greater than isogenic cultures following only 1-2 hours of incubation. Previously established methods of detecting lymphocyte transformation, such as H3-thymidine uptake, are lengthy (days) and have other limitations.